Joint, and aircraft structure

ABSTRACT

Provided is a joint and an aircraft structure wherein it is possible to position a member relative to a preform with high accuracy. A groove into which a plate member (30) is inserted is formed in a pi-shaped joint (20) provided on the preform (21), and the preform (21) and the plate member (30) are connected by being bonded. Moreover, a fitting shape (32A-1) into which the plate member (30) is fitted is formed on the pi-shaped joint (20) on the whole groove bottom face. Additionally, a fitting shape (32A-2) into which the plate member (30) is fitted is formed on a portion of the groove bottom face. Furthermore, fitting shapes (32B-1, 32B-2), into which the groove bottom face that is formed on the pi-shaped joint (20) is fitted, are formed on the surface of the plate material (30) that is fitted with the pi-shaped joint (20).

TECHNICAL FIELD

The present invention relates to a joint, and an aircraft structure.

BACKGROUND ART

In the aviation field, the range of application of composite materialssuch as, for example, carbon fiber reinforced plastics (CFRP) hasextended to the primary structure. Also, utilizing the advantage oflight weight of composite materials, it is desirable that joints do notuse fasteners, in order to achieve weight reduction of the structure.

The so-called pi (π) shaped joint in which a groove is formed and amember (for example a plate member) is inserted into the groove is anexample of a joint.

A plate member inserted into the joint is bonded using adhesive, and thejoint is also bonded to a preform using adhesive. In this way, platemembers are connected to a preform.

Also, when assembling the structure, plate members that are joined tothe preform must be positioned with high accuracy. In other words, ifthe joint is provided in advance on the preform, it is necessary toposition the plate member with respect to the joint with high accuracy.

In Patent Document 1, a peg (projection) for positioning is provided ona side face of a plate member, and a slot into which the peg is fittedis provided on a side face of a joint, and positioning is carried out byinserting the plate member so that the peg of the plate member is fittedinto the slot of the joint.

CITATION LIST Patent Literature

Patent Document 1: U.S. Pat. No. 8,403,586

SUMMARY OF INVENTION Technical Problem

However, in the configuration disclosed in Patent Document 1, it isnecessary to provide the projection in the side face of the platemember, and provide the slot in the side face of the joint, so thenumber of assembly operations is increased. Also providing the slot isnot desirable from the point of view of strength.

With the foregoing in view, it is an object of the present invention toprovide a joint and an aircraft structure that enables a member to bepositioned relative to a preform without increasing the number ofassembly operations and without reducing the strength.

Solution to Problem

In order to solve the problem described above, the joint and theaircraft structure according to the present invention utilize thefollowing means.

The joint according to a first aspect of the present invention isprovided on a preform, has a groove formed therein into which a memberis inserted, and is for connecting the preform and the member bybonding. A first fitting shape into which the member fits is formed onthe whole face of the bottom face of the groove.

The joint according to this aspect is provided on a preform, has agroove formed therein into which a member is inserted, and is forconnecting the preform and the member by bonding. Note that the memberis, for example, a plate member. The member is bonded to the joint byfilling the gap between the member and the groove with adhesive. Also,the joint is bonded to the preform with, for example, adhesive.

It is necessary that the member inserted into the joint is positionedwith good accuracy.

Also, a first fitting shape into which the member fits is formed on thewhole face of the bottom face of the groove. In other words, a fittingshape into which the first fitting shape fits is also formed on themember, and the first fitting shape on the bottom face of the groove isfitted with the fitting shape of the member. In this way, the member isfitted only in the position that corresponds with the first fittingshape.

Note that the first fitting shape is a shape that is symmetrical withrespect to the center of the groove width as axis, or a shape that isasymmetrical.

Therefore, according to the aspect as described above, the member can bepositioned with high accuracy with respect to the preform, withoutincreasing the number of assembly processes, and without reducing thestrength.

In the aspect as described above, a second fitting shape into which themember fits is formed on a portion of the bottom face of the groove.

According to this aspect, the second fitting shape is the standardposition for positioning the member with respect to the longitudinaldirection of the groove, so the member can be positioned in the requiredposition with respect to the longitudinal direction of the groove. Theshape of the second fitting shape is, for example, a protrusion shape ora slot shape.

In the first aspect as described above, the first fitting shape may beformed so that the position of the member is a prescribed position withrespect to the groove width.

According to this aspect, the member can be positioned in the prescribedposition with respect to the groove width. The prescribed position is aposition in which, for example, the member does not touch the two facesthat form the groove, such as the center of the groove width.

In the first aspect as described above, the joint may include: a mainbody member in which the groove is formed; and a positioning memberhaving the fitting shape formed on a top face thereof, and thepositioning member is arranged in the main body member so that the topface thereof is a bottom face of the groove, and the member is connectedat the top face.

According to this aspect, the joint is a so-called pi-shaped joint inwhich the groove is formed, the member is connected to the groove, andthe fitting shape is formed in advance by the positioning member. Notethat the main body member may be configured as separate from thepositioning member, or it may be formed integrally therewith.

The joint according to a second aspect of the present invention is ajoint provided on a preform, has a groove formed therein into which amember is inserted, and is for connecting the preform and the member bybonding. A first fitting shape is formed on a bottom face of the grooveto position the member with respect to the width direction of thegroove.

In the second aspect as described above, a second fitting shape isformed on the bottom face of the groove to position the member withrespect to the longitudinal direction of the groove.

The aircraft structure according to a third aspect of the presentinvention includes: the joint as described above; and a member in whicha fitting shape is formed, the fitting shape fitting with the bottomface of the joint at a connection face with the joint, and the member isconnected by inserting into the groove of the joint and bonding.

Advantageous Effects of Invention

The present invention has the advantageous effect that the member can bepositioned with high accuracy with respect to the preform.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view illustrating a partially sectioned mainwing of an aircraft.

FIG. 2 is a side view illustrating the configuration of a pi-shapedjoint according to an embodiment of the present invention.

FIG. 3 is a perspective view illustrating the configuration of api-shaped joint according to an embodiment of the present invention.

FIG. 4 is a side view illustrating the configuration of a pi-shapedjoint according to a first modification of the present invention.

FIG. 5 is a side view illustrating the configuration of a pi-shapedjoint according to a second modification of the present invention.

FIG. 6 is a perspective view illustrating the configuration of api-shaped joint according to a third modification of the presentinvention.

DESCRIPTION OF EMBODIMENTS

An embodiment of the joint and aircraft structure according to thepresent invention is described below with reference to the accompanyingdrawings.

The joint according to the present embodiment is a so-called pi (π)shaped joint (hereafter, “pi-shaped joint”) 20 (see FIG. 2) provided ona preform, and in which a groove is formed, a member being inserted intothe groove, and is for connecting the preform and the member by bonding.

FIG. 1 is a perspective view illustrating a partially sectioned mainwing 1 of an aircraft.

The main wing 1 includes an upper skin 3, a lower skin 5, a forward spar7, a rear spar 9, and a plurality of ribs 11.

The upper skin 3 and the lower skin 5 configure the outer shape of themain wing 1 and are thin plates also acting as aerodynamic surfaces.Along with the forward spar 7, the rear spar 9, and stringers (notillustrated), the upper skin 3 and the lower skin 5 partially beartensile loads and compressive loads acting on the main wing 1.

As illustrated in FIG. 1, the forward spar 7 and the rear spar 9 arestructural members that extend in the lengthwise direction of the mainwing 1, and are disposed between the upper skin 3 and the lower skin 5.

A plurality of stringers, which are support members extending in thelengthwise direction of the main wing 1, is disposed on the inside faceof the upper skin 3 or the lower skin 5, between the forward spar 7 andthe rear spar 9.

As illustrated in FIG. 1, the ribs 11 are structural members extendingin the widthwise direction of the main wing 1, and are disposed betweenthe upper skin 3 and the lower skin 5. In other words, the ribs 11 arestructural members extending in a direction roughly orthogonal to theforward spar 7 and the rear spar 9, and are plate-like members formed inthe shape of the cross-sectional shape of the main wing 1.

Here, a pi-shaped joint 20 according to the present embodiment is usedfor example in the connection between the upper skin 3 and the forwardspar 7 and the rear spar 9, the connection between the lower skin 5 andthe forward spar 7 and the rear spar 9, the connection between the ribs11 and the forward spar 7 and the rear spar 9, and the like. Note thatthe pi-shaped joint 20 may be used in structures other than the mainwing 1 of an aircraft.

FIG. 2 is a side view illustrating the configuration of the pi-shapedjoint 20 according to the present embodiment

The pi-shaped joint 20 provided on a preform 21 is configured from amain body member 24 in which a groove 22 is formed, and a positioningmember 26 (also referred to as a filler) with fitting shapes 32A-1,32A-2 (see also FIG. 3) formed on the top face 26A thereof.

The groove 22 of the pi-shaped joint 20 is formed by arranging two facesof a pair of L-shaped members 28 from which the main body member 24 isformed opposite each other, and configured so that the top face 26A ofthe positioning member 26 is the bottom face of the groove 22.

The pi-shaped joint 20 is, for example, used in the body structure of anaircraft as described above, and a member (a plate member 30 as anexample in the present embodiment) that forms a part of the bodystructure is inserted into the groove 22. For example the forward spar 7or the rear spar 9 is the preform 21, and the rib 11 is the plate member30.

Also the bottom face of the inserted plate member 30 is connected to thetop face 26A of the positioning member 26.

The fitting shapes 32A-1, 32A-2 (see also FIG. 3) which are described indetail later are formed in advance in the top face 26A of thepositioning member 26, and the position of the plate member 30 is fixedin the desired position by the fitting shapes 32A-1, 32A-2. In otherwords, the positioning member 26 has the function of positioning theplate member 30.

Also, the plate member 30 is bonded to the pi-shaped joint 20 by fillingthe gap between the plate member 30 and the groove 22 with adhesive. Onthe other hand, the pi-shaped joint 20 is bonded to the preform 21 withadhesive. Note that there is no particular limitation on the method ofbonding the preform 21 and the pi-shaped joint 20, and the method ofbonding the pi-shaped joint 20 and the plate member 30.

In this way, the plate member 30 is bonded to the preform 21 by bondingusing the pi-shaped joint 20, and without using fasteners.

The material of the pi-shaped joint 20, the preform 21, and the platemember 30 is a composite material, for example, carbon fiber reinforcedplastic (CFRP) or the like. In CFRP, carbon fiber is used as areinforcing material, and a synthetic resin is used as a matrix. Notethat this is not a limitation, and a metal such as aluminum alloy may beused as the material of the pi-shaped joint 20, the preform 21, and theplate member 30.

As illustrated in the enlarged view in FIG. 2, in the pi-shaped joint 20according to the present embodiment, the bottom face of the groove 22(hereafter referred to as the “groove bottom face”) is the top face 26Aof the positioning member 26. Therefore, the fitting shape 32A-1 intowhich the plate member 30 fits is formed on the whole face of the groovebottom face.

In this way, the fitting shape 32A-1 is formed across the whole groovebottom face, so the plate member 30 is positioned in plane. In otherwords, the fitting shape 32A-1 positions the plate member 30 withrespect to the width direction of the groove 22.

One example of the fitting shape 32A-1 according to the presentembodiment is a shape formed symmetrically about the center line CL ofthe width of the groove 22 (hereafter, the “groove width”) as axis, andin the example illustrated in FIG. 2 is a V-shape.

This V-shaped fitting shape 32A-1 is formed along the longitudinaldirection of the groove 22.

Note that the whole face of the groove bottom face 22A includessubstantially the whole face, but the fitting shape 32A-1 need not beformed in a portion of the groove bottom face 22A in the longitudinaldirection. For example the fitting shape 32A-1 need not be formed nearboth ends in the longitudinal direction of the groove bottom face 22A,the fitting shape 32A-1 need not be formed near the center in thelongitudinal direction of the groove bottom face 22A, and the fittingshape 32A-1 need not be formed at a plurality of locations in thelongitudinal direction of the groove bottom face 22A.

A fitting shape 32B-1 corresponding to the fitting shape 32A-1 of thegroove bottom face 22A is formed in the plate member 30 in theconnecting face with the pi-shaped joint 20. In the example of FIG. 2,the fitting shape 32B-1 formed in the plate member 30 is also V-shaped.By making both fitting shapes 32A-1, 32B-1 V-shaped, the plate member 30is smoothly fitted to the groove bottom face 22A.

Note that the fitting shape 32A-1 is formed so that the plate member 30is positioned in a prescribed position with respect to the groove width.

The prescribed position is a position such as, for example, the centerin the groove width, in which the plate member 30 does not contact thetwo faces of the L-shaped members 28 that form the groove 22. When theplate member 30 contacts the two faces of the L-shaped members 28 thatform the groove 22, it is not possible to uniformly fill with adhesiveon both sides of the plate member 30.

FIG. 3 is a perspective view illustrating the configuration of thepi-shaped joint 20 according to the present embodiment.

As illustrated in FIG. 3, a fitting shape 32A-2 into which the platemember 30 fits is formed in a portion of the groove bottom face 22A ofthe pi-shaped joint 20 according to the present embodiment. One exampleof the fitting shape 32A-2 according to the present embodiment is a slotshape.

In this way, the fitting shape 32A-2 is formed in a portion of thegroove bottom face 22A, so the plate member 30 is positioned at a point.In other words, the fitting shape 32A-2 is at a reference position forpositioning the plate member 30 with respect to the longitudinaldirection of the groove 22, and positions the plate member 30 withrespect to the longitudinal direction of the groove 22.

On the other hand, a fitting shape 32B-2 into which the fitting shape32A-2 fits is formed in the plate member 30. The fitting shape 32B-2according to the present embodiment has a protrusion shape that can fitwith the fitting shape 32A-2.

Also the fitting shapes 32A-1, 32A-2 of the groove bottom face 22A fitwith the fitting shapes 32B-2, 32B-2 of the plate member 30. In thisway, the plate member 30 is fitted in a position that coincides with thefitting shapes 32A-1, 32A-2 of the groove bottom face 22A.

Note that as an example there is one each of the fitting shapes 32A-2,32B-2 illustrated in FIG. 3, but this is not a limitation, and forexample two or more may be formed at equal intervals. In addition, asone example the fitting shapes 32A-2, 32B-2 are formed substantially inthe center in the longitudinal direction of the groove 22, but this isnot a limitation, and for example they may be formed near an end of thegroove 22.

In the example of FIG. 3, the L-shaped members 28 (main body member 24)and the positioning member 26 are separately configured, but theL-shaped members 28 (main body member 24) and the positioning member 26may be formed integrally. Note that there is no particular limitation onthe method of forming the L-shaped members 28 and the positioning member26 from which the pi-shaped joint 20 is configured.

As described above, the pi-shaped joint 20 according to the presentembodiment is provided on the preform 21, the groove 22 in which theplate member 30 is inserted is formed therein, and by bonding to thepreform 21 and the plate member 30 connects the preform 21 and the platemember 30. Moreover, the fitting shape 32A-1 into which the plate member30 fits is formed on the pi-shaped joint 20 on the whole groove bottomface 22A. Additionally, the fitting shape 32A-2 into which the platemember 30 fits is formed in a portion of the groove bottom face 22A.

On the other hand, the fitting shapes 32B-1, 32B-2 that fit with thegroove bottom face 22A formed in the pi-shaped joint 20 are formed onthe plate member 30 at the joining face with the pi-shaped joint 20.

Therefore, the pi-shaped joint 20 according to the present embodimentcan arrange the plate member 30 in the required position with respect tothe groove width using the fitting shape 32A-1 of the groove bottom face22A. In other words, the plate member 30 is positioned with highaccuracy with respect to the groove width (the direction A in FIGS. 2and 3) using the fitting shape 32A-1 of the groove bottom face 22A.

Also, the pi-shaped joint 20 according to the present embodimentpositions the plate member 30 with high accuracy with respect to thelongitudinal direction of the groove 22 (the direction B of FIG. 3)using the fitting shape 32A-2 of the groove bottom face 22A.

Also, by just inserting the plate member 30 into the pi-shaped joint 20according to the present embodiment towards the groove bottom face 22A,the plate member 30 is positioned with high accuracy with respect to thevertical direction of the groove 22 (the direction C of FIGS. 2 and 3).

Also, the pi-shaped joint 20 according to the present embodimentprevents the plate member 30 from being connected to the pi-shaped joint20 at an inclination by fitting with the plate member 30 using thefitting shapes 32A-1, 32A-2.

Furthermore, the fitting shapes 32A-1, 32A-2 are formed in advance onthe pi-shaped joint 20, and the fitting shapes 32B-1, 32B-2 are formedin advance on the plate member 30. Therefore, by just inserting theplate member 30 into the pi-shaped joint 20, the plate member 30 can bepositioned, so compared with the conventional method in which forexample a positioning peg is used, the process of assembling thestructure can be simplified, and the time required for assembly can beshortened.

First Modification

Hereinafter, a first modification of the present invention will bedescribed.

FIG. 4 is a side view of the pi-shaped joint 20 according to a firstmodification of the present invention. Note that constituent parts inFIG. 4 that are the same as in FIG. 2 are given the same reference signsas in FIG. 2, and their description is omitted.

The fitting shape 32A-1 of the groove bottom face 22A according to thefirst modification is formed asymmetrically about the center line CL ofthe groove width as axis.

As illustrated in FIG. 4, in the first modification, the fitting shape32A-1 is formed in a circular arc-shaped (radiused shape) protrusion insubstantially the center, and on the two sides thereof is formed in aflat shape with different heights.

On the other hand, a circular arc-shaped recess with flat shapes withdifferent heights on the two sides thereof is formed in the plate member30 as the fitting shape 32B-1 into which the fitting shape 32A-1 fits.

Second Modification

Hereinafter, a second modification of the present invention will bedescribed.

FIG. 5 is a side view of the pi-shaped joint 20 according to the secondmodification of the present invention. Note that constituent parts inFIG. 5 that are the same as in FIG. 2 are given the same reference signsas in FIG. 2, and their description is omitted.

The fitting shape 32A-1 of the groove bottom face 22A according to thesecond modification is formed asymmetrically about the center line CL ofthe groove width as axis.

As illustrated in FIG. 5, in the second modification, a slanting face(tapered shape) is formed on a first side of the fitting shape 32A-1,and a flat shape with a step is formed on a second side.

On the other hand, a slanting face is formed on one side, and a flatshape with a step is formed on a second side in the plate member 30 asthe fitting shape 32B-1 into which the fitting shape 32A-1 fits.

Third Modification

Hereinafter, a third modification of the present invention will bedescribed.

FIG. 6 is a side view of the pi-shaped joint 20 according to the thirdmodification of the present invention. Note that constituent parts inFIG. 6 that are the same as in FIG. 3 are given the same reference signsas in FIG. 3, and their description is omitted.

As illustrated in FIG. 6, in the pi-shaped joint 20 according to thethird modification, a protrusion shape is formed in the positioningmember 26 as the fitting shape 32A-2.

On the other hand, a slot shape is formed in the plate member 30 as thefitting shape 32B-2 into which the fitting shape 32A-2 fits.

The present invention has been described using the above embodiments,but the technical scope of the present invention is not limited to thescope of the embodiments as described above. Various modifications orimprovements can be made to the embodiments as described above withinthe range that does not deviate from the intent of the invention, andthese forms to which the modifications or improvements have been addedare also included within the technical scope of the present invention.

For example, in the embodiments as described above, the pi-shaped joint20 was described for a form used in an aircraft structure, but thepresent invention is not limited to this, and the pi-shaped joint 20 maybe a form that is used in structures other than an aircraft.

Also, in the embodiments as described above, a form was described inwhich the fitting shape 32A-1 and the fitting shape 32A-2 are formed inthe positioning member 26, and the fitting shape 32B-1 and the fittingshape 32B-2 are formed in the plate member 30, but the present inventionis not limited to this. For example, the fitting shape 32A-1 only may beformed in the positioning member 26, and the fitting shape 32B-1 onlymay be formed in the plate member 30.

REFERENCE SIGNS LIST

-   1 Main wing-   20 Pi-shaped joint-   21 Preform-   22 Groove-   24 Main body member-   26 Positioning member-   30 Plate member-   32A-1 Fitting shape-   32A-2 Fitting shape-   32B-1 Fitting shape-   32B-2 Fitting shape

The invention claimed is:
 1. A joint provided on a preform and forconnecting the preform and a member by bonding, the joint comprising: agroove formed therein into which the member is inserted; a pair of firstportions arranged opposite to each other, opposite faces thereof formingboth sides of the groove; a second portion arranged between the pair ofthe first portions and forming a bottom face of the groove; and a firstfitting shape into which the member fits, and that is formed entirely ona face forming the bottom face of the groove, wherein the first fittingshape is formed asymmetrically with respect to a center line of a widthof the groove.
 2. The joint according to claim 1, wherein a secondfitting shape into which the member fits is formed on a portion of thebottom face of the groove.
 3. The joint according to claim 1, whereinthe first fitting shape is formed so that the member is positioned in aprescribed position with respect to the width of the groove.
 4. Thejoint according to claim 1, further comprising: a main body member inwhich the groove is formed, wherein the second portion is a positioningmember having the first fitting shape formed on a top face thereof, thepositioning member is arranged in the main body member so that the topface thereof is the bottom face of the groove, and the member isconnected at the top face.
 5. An aircraft structure, comprising: thejoint described in claim 1, wherein the member includes a fitting shape,the fitting shape fitting with the bottom face of the groove at aconnection face with the joint, the member being inserted into thegroove of the joint and connected to the groove of the joint by bonding.6. A joint provided on a preform and for connecting the preform and amember by bonding, the joint comprising: a groove formed therein intowhich a member is inserted; a pair of first portions arranged oppositeto each other, opposite faces thereof forming both sides of the groove;a second portion arranged between the pair of the first portions andforming a bottom face of the groove; and a first fitting shape beingformed in a face forming the bottom face of the groove, to position themember with respect to a width direction of the groove, wherein thefirst fitting shape is formed asymmetrically with respect to a centerline of a width of the groove.
 7. The joint according to claim 6,wherein a second fitting shape is formed on the bottom face of thegroove to position the member with respect to a longitudinal directionof the groove.
 8. An aircraft structure, comprising: the joint describedin claim 6, wherein the member includes a fitting shape, the fittingshape fitting with the bottom face of the groove at a connection facewith the joint, the member being inserted into the groove of the jointand connected to the groove of the joint by bonding.